So-Called HIV 'Cure' Is Not Actually a Cure

A nurse tests a blood sample for HIV. Athit Perawongmetha / Reuters

In recent years, there have been several claims that HIV was cured in different people, but these proclamations haven't generally panned out.

There was the case of an infected Mississippi baby given antiretroviral drugs shortly after birth, who was declared "functionally cured" in March 2013. This summer, doctors detected HIV in her blood.

Also over the summer, doctors found that two men who had been given an aggressive cancer treatment had undetectable HIV levels. Their doctors held out hope the two men were cured. But once again the virus came back, months later.

And now, Agence France-Presse (and several other outlets) is reporting that two patients in France have experienced an "apparent spontaneous cure."

As detailed in a study to be published in Clinical Microbiology and Infection, a team of French researchers describe the case of two men infected years ago (one of them 30 years in the past) who never developed AIDS and have undetectable levels of HIV.

"The AIDS-causing virus remained in their immune cells but was inactivated because its genetic code had been altered," the AFP reports. "The change appeared to be linked to increased activity of a common enzyme named APOBEC, [the researchers] theorized."

The hypothesis put forward by the researchers is that in these patients this enzyme altered the genetics of HIV so that it couldn't infect immune cells and turn them into virus factories, which is how HIV typically operates.

These individuals are examples of "elite controllers," the article continues. This term is used to refer to a small subset (less than 1 percent) of HIV patients who never develop AIDS—the immune-depleted state that usually follows the virus and opens up the door to some other opportunistic infection, which can ultimately lead to death.

However, it is wholly inaccurate to call this a "cure," and the methods used in the study were not high quality, said an American HIV researcher who wishes to remain anonymous because he was not authorized by his institution to speak on the matter. Specifically, the study authors used a clinical test to look for HIV in the patients' blood. The clinical test is more widely available and less expensive than the standard laboratory methods that are typically used, but it's also 10 times less sensitive, the researcher tells Newsweek.

This matters greatly because even "elite controllers" typically have viruses in their blood, but at levels so low that they can be detected only by the most sensitive assays, he says. So it's highly probable that these patients do in fact have HIV in their bloodstream but it isn't showing up using the clinical test.

This would make them no more or less special than other "elite controllers," the researcher adds.

Next the researchers analyzed sequences of DNA that the HIV had inserted into the patients' immune cells (which is also a standard behavior of the retrovirus). From this analysis, they concluded that the retrovirus had been altered and "inactivated" by the APOBEC enzyme. But this is hardly surprising. APOBEC is a standard component of the immune cells the retrovirus targets, and the enzyme's function is exactly that: to induce mutations in HIV to render it harmless.

But this usually doesn't work, because HIV reproduces so quickly and mutates on its own, allowing it to evade APOBEC. And even if it is affected by APOBEC, HIV can still be infectious and continue spreading through the body, the researcher says.

It is possible that an APOBEC-led attack could have rendered these patients' HIV noninfectious, but it's highly unlikely, because it would have had to occur early on when the retrovirus was infecting only a few cells in the body, according to the researcher. "The most important effect is probably early on, when HIV is only affecting one or two cells. Once the virus takes off, it's too late," he adds. And these patients showed evidence of antibodies against the virus, suggesting a significant quantity of virus at some point in the past.

There could be many reasons why these patients are elite-controllers, and it's indeed worthwhile to study such people to see why they might be resistant to HIV, the researcher says. But it's unfair to use the C-word.

"The depth of analysis is insufficient to fit the conclusion—the hypothesis is cool, but they jumped the gun" on calling it a cure, he says.

The only person to be "cured' of HIV is Timothy Brown, also known as the "Berlin patient," who received a bone marrow transplant from somebody who was genetically resistant to the pathogen.